The application of electronic control to internal combustion engine intake air metering is generally known in the art of engine control. Typically, such control includes a controlled actuator connected to a throttle valve, such as a conventional butterfly valve, wherein valve position is adjusted by controlled actuator motion to provide appropriate restriction on air passage into the engine. The actuator is in communication with a controller which controls actuator motion when air is to be metered to the engine. The controller may be responsive to any one of several ingredients used to formulate the current desired throttle position. For example, such ingredients may include inputs indicative of the engine operating condition, an operator command from an accelerator pedal, or information from an active cruise control algorithm, an active idle speed control algorithm, or an active traction control algorithm. Further, feedback may be provided to the controller, such as from a conventional throttle valve position sensor communicating a signal to the controller the magnitude of which is related to the degree of opening of the throttle valve. Corrective positioning of the actuator or diagnostics may be carried out by the controller in response to the sensor feedback signal.
The advantages of electronic control of intake air metering are well known. For example, an important advantage is that the electronic control may replace the traditional, substantially inflexible cable assembly connecting the vehicle accelerator pedal or its equivalent and the throttle valve. The electronics provide opportunities in vehicle control and diagnostics that were unavailable traditionally. A control opportunity resides in determining and acting on operator intent, which may not be most accurately reflected in traditional driver inputs.